Determined for housing units at the time of enumeration. Vacancy status pertains to year-round vacant units. Vacancy status and other characteristics of vacant units are determined by enumerators questioning landlords, owners, neighbors, rental agents, and others.

The housing inventory includes vacant mobile homes or trailers intended to be occupied on the site where they stand. Vacant mobile homes on dealer sales lots or in storage yards are not counted as housing units.

New units not yet occupied are classified as vacant housing units if construction has reached a point where all exterior windows and doors are installed and final usable floors are in place. Vacant units are excluded if open to the elements; that is, if the roof, walls, windows, or doors no longer protect the interior from the elements, or if there is positive evidence (such as a sign on the house or in the block) that the unit is to be demolished or is condemned. Also excluded are quarters being used entirely for nonresidential purposes, such as a store or an office, or quarters used for the storage of business supplies or inventory, machinery, or agricultural products.

Vacant year-round units offered for sale only. The category includes mainly one-family houses, but also two types of vacant units in multi-unit buildings: (1) vacant units (which are for sale only) in a cooperative or condominium and (2) vacant units intended to he occupied by the new building owners in multi-unit buildings that are for sale. 4n individual unit that is vacant because it is being held for sale of the entire building is classified as "other vacant." Vacant units offered for rent or sale at the same time are classified as "for rent."

Vacant units for year-round occupancy not classified above, for example, units held for a janitor or caretaker, settlement of an estate, pending repairs or modernization, or personal reasons of the owner.

Vacant units used or intended for use only in certain seasons. Any unit used throughout the year, even if only occasionally, is excluded. Seasonal units include those used for summer or winter sports or recreation--beach cottages and hunting cabins, for example. Seasonal units may also include quarters for such workers as herders and loggers. Migratory units include those for farm workers during crop season.